Process and device for cutting tobacco leaves

ABSTRACT

In a process for obtaining from tobacco leaves fragments of substantially constant shape and more particularly the shape of a quadrilateral having parallel opposite sides, wherein the leaves are subjected to a cutting operation along parallel and equidistant cutting lines, the fragments obtained are subjected to an orientation operation so that the cutting lines should assume a first given direction and the fragments which are thus oriented are caused to undergo a recutting operation along equidistant recutting lines which are parallel to a second given direction, the step of separating from all the oriented fragments which are caused to undergo the recutting operation all those fragments whose projection on a line at right angles to said second direction is smaller in length than the distance between said recutting lines.

United States Patent Pietrucci et al.

[151 3,659,620 [4 1 May 2,1972

[54] PROCESS AND DEVICE FOR CUTTING TOBACCO LEAVES [72] inventors: Andre Pietrucci; Pierre Imbert, both of Fleury-Les-Aubrais, France [21] App1.No.: 889,668

FOREIGN PATENTS OR APPLICATIONS 1,472,587 1/1967 France ..131/149 264,629 9/1913 Germany... ...131/149 879,818 6/1953 Germany ..l3l/149 Primary Examiner-Samuel Koren Assistant Examiner-J. F. Pitrelli Attorney-Sparrow and Sparrow [57] ABSTRACT In a process for obtaining from tobacco leaves fragments of substantially constant shape and more particularly the shape of a quadrilateral having parallel opposite sides, wherein the leaves are subjected to a cutting operation along parallel and equidistant cutting lines, the fragments obtained are subjected to an orientation operation so that the cutting lines should assume a first given direction and the fragments which are thus oriented are caused to undergo a recutting operation along equidistant recutting lines which are parallel to a second given direction, the step of separating from all the oriented fragments which are caused to undergo the recutting operation all those fragments whose projection on a line at right angles to said second direction is smaller in length than the distance between said recutting lines.

9 Claims, 7 Drawing Figures Plhnted May 2, 1972 4 Shuts-Shut 1 aNVENTm SI Amuse Hfluc1 Pleas II-185121" B I y SPARRQW av) fARR-ow Patented May 2, 1972 3,659,620

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PROCESS AND DEVICE FOR CUTTING TOBACCO LEAVES This invention relates to a process and device for obtaining from tobacco leaves which are in principle naturalv tobacco leaves fragments of substantially constant geometrical shape such as in particular the shape of a quadrilateral having parallel opposite sides and especially squares and rectangles.

In order to obtain fragments of rectangular shape from tobacco leaves, it has already been proposed to subject the leaves to two successive cutting operations in substantially perpendicular directions. However, a large proportion of fragments having very different shapes and sizes were mixed with uniformly cut fragments since no provision was made for sorting or screening between the two cutting operations.

The invention is intended to obtain a very good uniformity of shreds and is directed to a process for obtaining from tobacco leaves fragments of substantially constant shape and more especially the shape of a quadrilateral having parallel opposite sides of the type wherein the leaves are subjected to a cutting operation along parallel and equidistant cutting lines, the fragments obtained are subjected to an orientation operation so that their cutting lines should assume a first given direction and the fragments which are thus oriented are caused to undergo a recutting operation along equidistant recutting lines which are parallel to a second given direction. The process essentially consists in separating from all the oriented fragments which are caused to undergo the recutting operation all those fragments whose projection on a line at right angles to said second direction is smaller in length than the distance between said recutting lines.

The invention is also directed to a device for the practical application of the process. The device in accordance with the invention comprises essentially cutting means, orientation means located downstream of the cutting means, separating or screening means located downstream of the orientation means and recutting means located downstream of the separating means.

The recutting means can be combined with the cutting means provided of course that the orientation means are adapted to orient those fragments which have undergone the cutting operation in a direction which is different from that of the cutting lines.

The invention will be explained in greater detail by means of practical examples, reference being made to the accompanying drawings, in which: I

FIG. 1 is a vertical sectional view of one complete embodiment of the device according to the invention;

FIG. 2 is a sectional view along line 11-11 of FIG. 1;

FIG. 3 is a diagrammatic view of the vibrating conveyor of FIGS. 1 and 2;

FIG. 4 is a vertical sectional view of another embodiment;

FIG. 5 is a top view of the device of FIG. 4;

FIG. 6 is a block diagram of an assembly. according to the invention in which the cutting and recutting means are combined;

FIG. 7 is a block diagram of an assembly comprising cutting and recutting means which differ from each other.

Before describing the forms of construction which are illustrated in FIGS. 1 to 5, the principle of the invention will now be described with reference to the diagram of FIGS. 6 and 7.

In the example of FIG. 7, the device as a whole comprises a tobacco-leaf supply unit 40 and this latter feeds the cutting unit 29 which is adapted to cut the leaves along parallel and equidistant lines. The leaf fragments which are cut to shape by the unit 29 are conveyed along the path 41 to the orientation unit 31, the leaves being accordingly oriented in a given direction which is in principle the same as that of the cutting lines produced by the unit 29. From the unit 31, the fragments which are thus oriented follow the path 42 so as to pass through separating or screening means 33.

There is placed downstream of said means 33 a recutting unit 30 which is adapted to cut the fragments along equidistant cutting lines which are parallel to a direction other than that which is given by the unit 3].

The means 33 are adapted to separate from thestream of fragments which has followed the path-42 all those fragments whose projection on a line at right angles to the direction of the recutting lines is shorter than the distance between said recutting lines. Only those fragments whose projection is of greater length follow the path 43 in order to be subjected to the recutting operation by the unit 30 and to be discharged along the path 44.

Some of the fragments whose length of projection is smaller than said distance have at least one dimension which is greater than the distance between recutting lines but are badly oriented; these fragments are brought back along the path 45 to a point downstream of the orientation unit 31 on the path 41. Those fragments which have a dimension equal to the distance between recutting lines are reintroduced via the path 46 into the stream which passes out of the unit 30 along the path 44.

Finally, the other out fragments can be removed along the path47.

In the example of FIG. 6, the cutting unit 29 and recutting unit 30 are combined. However, the same means and the same paths as those of FIG. 7 are again shown and bear the same reference numerals.

In the exemplifiedembodiment of FIGS. 1 to 3, the first cutting unit 29 is of a type comprising discs 1 and spacer members 2 and comprises means for removing the cut shreds.

The material to be cut is introduced by means of a vibrating conveyor 3 having a width equal to the useful portion of the cutter 29 and coupled to the cutting unit 29 by means of a system of spaced belts 4 which make it possible for a large proportion of the small fragments of the mixture (those whose mean diameter is smaller than the intended width of cut) to pass through the belt system; these fragments can then be transferred onto a conveyor 5 so as to be introduced directly into the calibrated product at the outlet of the device or onto the vibrating surface.

The unit 29 itself is in this case oriented at right angles to the direction of the grooves of the vibrating surface 3.

The shreds obtained as a result of the cutting operation are withdrawn by means of the moving belts 4 which pass over'the spacer members of the cutting units (and which are driven by said members): the bottom run of each set of belts then passes over a roller 6. In the example under consideration, the product withdrawal belts are the feed belts 4 which pass over the spacer members 2 of the elements of the cutting unit 29 (as shown in FIG. 2). The guide rollers 7 are fitted with tensioning devices 8.

Those fragments which are cut by the first cutting unit 29 fall onto a vibrating surface 31 which is very close to this latter in order to prevent any out shreds from becoming disordered.

The vibrating surface 31 is essentially constituted (as shown in FIG. 3) by a belt conveyor 9, a vibrator 12, a reduction-gear motor 14 and a supporting assembly 16.

The belt conveyor 9 consists of an endless belt mounted on two guide rollers 19 and 20, the shafts of which are rotatably mounted at the ends of the frame 13, and the conveyor. belt has surface elevations and depressions in the form of bellowstype pleats 10.

The surface of the pleats must be rough in order to impart vibratory motion to the cut shreds; moreover, the length of the conveyor belt must be sufficiently great to ensure that the shreds have time to fall into position in the bottom of the pleats.

The conveyor belt 9 is provided with retaining sides 11 and at the downstream end with a shell 21 which retains the cut shreds in the bottom of the pleats in order that said shreds should be discharged only on the return run of the conveyor belt under the action of gravity.

The vibrator 12 is a motor having an unbalanced mass which is fixed on the frame 13 of the coupling system at the center of gravity of the complete assembly (including the elements mentioned hereinafter); the design function of said vibrator is to impart the vibratory motion described above to the belt conveyor.

The reduction-gear motor 14 is intended to carry out the translational motion of the conveyor belt through the intermediary of the driving means 15; this element forms part of the moving system (which is subjected to vibrations).

The supporting assembly from which the complete system is suspended is made up of four rods 16 which are secured to the frame 13 of the conveyor belt 9 at preferential locations (the diagonals of the rectangle which is materialized by the four points of attachment must intersect vertically above the center of gravity of the vibrator 12); said rods are carried by an external frame 17 and attached to this latter by means of four coil springs 18 (which permit vibrations). The eight points of attachment are articulated.

The essential cutting portion of the second cutting unit 30 is wholly similar in design to the first. However, this unit is provided in addition with a special feed system which is intended to ensure the introduction of shreds without disturbing their arrangement. a

From the upstream end to the downstream end, the assembly comprises a perforated rotary cylinder 22, a system of belts 23, a diversion device 24, a cutter 30.

The perforated rotary cylinder 22 is placed immediately beneath the downstream end of the shell 21. The surface of the cylinder is subjected to internal suction over a half-circumference (on the left-hand side in the diagram) in order to prevent any sliding at the time of transfer of shreds and dropping of these latter during the rotation (one-half revolution).

Moreover, the linear peripheral velocity is high (substantially higher than the rate of forward motion of the conveyor belt referred to above) in order to prevent the formation of wads of shreds on the surface of the cylinder.

The system of belts 23 (with tensioningdevice 26) is similar in design to the system described earlier and passes around the cylinder 22 over the suction portion of this latter and then, after a free path, introduces the fragments into the cutting unit 30, then withdraws the cut fragments. The whole assembly is driven by means of the spacer members of the halfunit concerned (one belt passes over each spacer member).

The device 33 for separating or diverting badly oriented shreds and small fragments is constructed as follows:

lnthe free portions of the belts 23, the fragments which are undersize and the shreds which are oriented lengthwise have a tendency to fall between the belts; these shreds and fragments are collected by a small vibrating'screening conveyor (having two levels 24 and 25) which transfers theshreds to the upstream end of the belt 9 andthe small fragments to the discharge end of the second cutting unit 30.

The cutter proper is equipped in the same manner as the first with discs 1 and spacer members 2.

The orientation of the input belts (inclination to the horizontal) is such that the fragments penetrate tangentially to the discs 1.

Provision is made for an admission shell 27 which is intended to facilitate the penetration of the fragments and for an air-blowing system 28 which permits the withdrawal of the cut fragments and prevents the dispersion of the stream prior to penetration of this latter into the discharge spout.

The device can be caused to operate with a single cutting unit in the following manner. At the discharge end of the grooved conveyor belt 9 and after removal via the unit 33 of fragments which have already been calibrated and badly oriented shreds, the stream is collected by a means which maintains the arrangement of the fragments (suction belt, for example) and is conveyed to the admission end of the unit 29; this unit would then have two separate intakes per belt system (one on each side).

In the example of construction of FIGS. 4 and 5, the cutting units 29 and 30 are again shown and are similar to those of the previous embodiments. The orientation means 31 consist of a vibrating plate 3land a conveyor 33. The vibrating plate 31 is providedwith grooves 32 which are oriented at right angles to the axis of the cutters 29. As will be readily apparent, the

vibrations which are imparted to the plate 31 by means of an excitation system (not shown) are oriented in the direction of the grooves 32. The downstream end of the plate is cut diagonally and placed above and as close as possible to the cleats 34 of the conveyor belt 33. Said cleats 34 are oriented at right angles to the direction of the grooves 32. As in the previous example, the conveyor 33 is made up of spaced belts between which undersize or badly oriented fragments are permitted to fall. There are mounted on the guide roller 36 of the belts 33 and between these latter smooth belts 37 which are passed around the spacer members 2 of the elements of the cutting unit 30. Said smooth belts serve to supply material to said unit.

A rotary component consisting of a shaft 38 adapted to carry radial teeth 39 is disposed beneath the top face of the belts 37 in such a manner that the teeth 39 should rotate in planes at right angles to said top face and intersect this latter. The teeth 39 rotate in the same direction but at a slightly higher speed than the belts 37. Under these conditions, a badly oriented shred is either straightened if its front extremity is driven by one tooth or, alternatively, is totally out of alignment and is in that case driven by one tooth at its downstream extremity.

What is claimed is: v

1. In a process for obtaining from tobacco leaves fragments of substantially constant shape and more particularly the shape of a quadrilateral having parallel opposite sides, wherein the leaves are fed into a stream and subjected to a cutting operation along parallel and equidistant cutting lines, the fragments obtained are subjected to an orientation operation so that the cutting lines are intended to assume a first given direction and the fragments which are thus oriented are caused to undergo a recutting operation along equidistant recutting lines which are parallel to a second given direction, the step of separating from said stream all the oriented fragments prior to said recutting operation whose projection on a line at right angles to said second direction is smaller in length than the distance between said recutting lines.

2. In a process according to claim 1, the further step of subjecting again to orienting and recutting operations those fragments which have been separated from said stream prior to said recutting operation and at least one dimension of which is greater than the distance between two recutting lines;

3. In a process according to claim 1, the further step of reintroducing in the stream of fragments which have been subjected to the recutting operation those fragments which have been separated from said stream prior to said recutting operation and one dimension of which is equal to the distance between two recutting lines.

4. In a device for obtaining from a stream of tobacco leaves fragments of substantially constant shape and more particularly the shape of a quadrilateral having parallel opposite sides, comprising cutting means adapted to cut the leaves along parallel and equidistant cutting lines, means for orienting the fragments obtained and adapted to set their cutting lines in a first given direction, recutting means adapted to recut the oriented fragments along recutting lines which are equidistant and parallel to a second given direction and the means for conveying the oriented fragments to said recutting means, separating means adapted to separate from said stream of oriented fragments prior to the recutting operation all those fragments whose projection on a line at right angles to said second direction is smaller in length than the distance between said recutting lines.

5. In a device according to claim 4, further comprising means for returning to said orienting means those fragments which have been separated by said separating means and at least one dimension of which is greater than the distance between two recutting lines.

I 6. In a device according to claim 4, further comprising means for reintroducing in the stream of fragments, which have been cut by said recutting means, those fragments which have been separated by said separating means and one dimen- 9. in a device according to claim 4, said means for conveying the oriented fragments to said recutting means comprising a first assembly of moving parallel endless belts set at a distance from each other corresponding to the spacing of said recutting lines and a second assembly of moving parallel endless belts adapted to pass on the one hand between the belts of said first assembly and on the other hand between the cutting elements of said recutting means.

i I I I i 

1. In a process for obtaining from tobacco leaves fragments of substantially constant shape and more particularly the shape of a quadrilateral having parallel opposite sides, wherein the leaves are fed into a stream and subjected to a cutting operation along parallel and equidistant cutting lines, the fragments obtained are subjected to an orientation operation so that the cutting lines are intended to assume a first given direction and the fragments which are thus oriented are caused to undergo a recutting operation along equidistant recutting lines which are parallel to a second given direction, the step of separating from said stream all the oriented fragments prior to said recutting operation whose projection on a line at right angles to said second direction is smaller in length than the dIstance between said recutting lines.
 2. In a process according to claim 1, the further step of subjecting again to orienting and recutting operations those fragments which have been separated from said stream prior to said recutting operation and at least one dimension of which is greater than the distance between two recutting lines.
 3. In a process according to claim 1, the further step of reintroducing in the stream of fragments which have been subjected to the recutting operation those fragments which have been separated from said stream prior to said recutting operation and one dimension of which is equal to the distance between two recutting lines.
 4. In a device for obtaining from a stream of tobacco leaves fragments of substantially constant shape and more particularly the shape of a quadrilateral having parallel opposite sides, comprising cutting means adapted to cut the leaves along parallel and equidistant cutting lines, means for orienting the fragments obtained and adapted to set their cutting lines in a first given direction, recutting means adapted to recut the oriented fragments along recutting lines which are equidistant and parallel to a second given direction and the means for conveying the oriented fragments to said recutting means, separating means adapted to separate from said stream of oriented fragments prior to the recutting operation all those fragments whose projection on a line at right angles to said second direction is smaller in length than the distance between said recutting lines.
 5. In a device according to claim 4, further comprising means for returning to said orienting means those fragments which have been separated by said separating means and at least one dimension of which is greater than the distance between two recutting lines.
 6. In a device according to claim 4, further comprising means for reintroducing in the stream of fragments, which have been cut by said recutting means, those fragments which have been separated by said separating means and one dimension of which is equal to the distance between two recutting lines.
 7. In a device according to claim 4, said orientation means being constituted by a vibrating grooved surface.
 8. In a device according to claim 7, said vibrating grooved surface comprising an endless belt having grooves oriented at right angles to the direction of forward travel of said belt and a vibrating device adapted to impart vibrations to said belt in a direction parallel to said grooves.
 9. In a device according to claim 4, said means for conveying the oriented fragments to said recutting means comprising a first assembly of moving parallel endless belts set at a distance from each other corresponding to the spacing of said recutting lines and a second assembly of moving parallel endless belts adapted to pass on the one hand between the belts of said first assembly and on the other hand between the cutting elements of said recutting means. 